Abstract

VILLANUEVA-OLEA, Rafael et al. Columnar crinoid plates from Las Delicias Formation, lower and middle Permian of Coahuila, Mexico. Bol. Soc. Geol. Mex [online]. 2021, vol.73, n.1, 00002.  Epub Oct 11, 2021. ISSN 1405-3322.  https://doi.org/10.18268/bsgm2021v73n1a040820.

Thirteen parataxa of crinoid plates from two localities of the lower-middle Permian of the Las Delicias Formation are deseribed. Both zones are situated in Sierra de las Delicias, to southwestern Coahuila state. The parataxa Pentagonopternix coahuilensis n. sp., Cyelocaudex typicus. C. insaturatus. C. cf. insaturatus. Cyelocaudex sp., Floricyelus diminuta n. sp., Floricyelus sp. Preptopremnum rugosum, P laeve, Preptopremnum sp., Heterostelechus keithi, Cyelocaudiculus regularis and Epierinus torreonense new genus and species were found in Las Difuntas locality of the middle Permian (Wordian Capitanian) whereas Cyelocaudex typicus, C. sp., Preptopremnum laeve and Epierinus torreonense were also found in Las Sardinas locality whose strata have been dated as early Permian (Kungurian-Roadian). The oceurrence of all parataxa in strata from the middle Permian of the Las Delicias Formation allowed extending their stratigraphic range until the Wordian Capitanian. Most species deseribed have been associated to the Grandian Paleoprovince, nonetheless, the presence of Floricyelus and Pentagonopternix parataxa in the Permian of Coahuila proves the cosmopolitan nature of both genera.

Keywords : Crinoidea; columnal plates; Permian; Las Delicias Formation; Coahuila; México.